diff --git a/tyxml-syntax.opam b/tyxml-syntax.opam
index 2a5064fc4..5c04ead8b 100644
--- a/tyxml-syntax.opam
+++ b/tyxml-syntax.opam
@@ -9,7 +9,7 @@ doc: "https://ocsigen.org/tyxml/latest/manual/intro"
 bug-reports: "https://github.com/ocsigen/tyxml/issues"
 depends: [
   "dune" {>= "2.7"}
-  "ocaml" {>= "4.03"}
+  "ocaml" {>= "4.04"}
   "alcotest" {with-test}
   "ppxlib" {>= "0.18"}
   "re" {>= "1.5.0"}
diff --git a/tyxml.opam b/tyxml.opam
index 3f9b2e251..d6384fd8f 100644
--- a/tyxml.opam
+++ b/tyxml.opam
@@ -11,7 +11,7 @@ doc: "https://ocsigen.org/tyxml/latest/manual/intro"
 bug-reports: "https://github.com/ocsigen/tyxml/issues"
 depends: [
   "dune" {>= "2.7"}
-  "ocaml" {>= "4.03"}
+  "ocaml" {>= "4.04"}
   "alcotest" {with-test}
   "re" {>= "1.5.0"}
   "seq"